The present disclosure relates to a touch detection circuit to be used in a capacitance-type touch panel, a touch detection method, and an electronic apparatus including such a touch detection circuit.
Recently, a touch panel is mounted in various electronic apparatuses such as: a handheld terminal including a smartphone; a portable video game player; and a personal computer. Such electronic apparatuses eliminate necessity of a previously-used keyboard or button, leading to reduction in size of each apparatus. Moreover, various user interfaces for the touch panel have been developed, allowing a user to more instinctively perform information input or operation. Consequently, the touch panel becomes increasingly important as a user interface.
There are various types of touch panels, such as a capacitance-type, an optical type, and a resistance-type. In particular, the capacitance-type touch panel is characteristically capable of detecting a human finger or the like not only when the finger is in contact with a touch detection surface but also when the finger is in proximity to the touch detection surface. This allows diverse user interfaces to be achieved. Hence, the capacitance-type touch panel is becoming used for various electronic apparatuses.
When an electronic apparatus is operated using such a touch panel, one user may operate the touch panel with a plurality of fingers, or a plurality of users may operate the touch panel. In such a case, it is necessary for the touch panel to detect a plurality of touches (multi-touch). For example, Japanese Unexamined Patent Application Publication No. 2011-23012 and publication of US patent application 2009/0284495A1 each disclose a capacitance-type touch panel capable of detecting multi-touch.